A mustache of semen (cum) that is delacately layed on the upper lip of a female, or in a homosexuals case on the upper lip of a man. This can be licked off by any partner and deposited into a sink or swallowed. Make sure there are no STD's while preforming this sexual activity. Best done after oral sex.
Dude i was gettin head from this chick and i cumed on her face and made a cumstache outta it... it was gnarly. it was a true work of art! She swallowed it and everything!